Physical evaluation and electrical properties in glassy semiconductors a-GeTe4Mx

Amorphous films of the ternary GeTe4Mx, where M=In and Cu and x represented by 0.05 and 0.10 with thickness about 200 nm, have been prepared by thermal evaporation. Dark conductivity measurement on thin films are reported in the temperature range 100–350 K. The results indicate that at the first slope which is represented by the range from 250 to 350 K, the conduction occurs in the band tails of localized states and at the second slope which is represented by the range from 100 to 250 K, the conduction is due to variable range hopping, which is in reasonable agreement with Mott’s condition of variable range hopping conduction.